<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>字面量</title>
</head>
<body>
<script>
  1; false; true; "abc"; undefined; NaN; 12.3;

  let value = 1
  value = 'abc'
  value = false
  value = undefined
  value = null

  console.log('value =>', value)
</script>
</body>
</html>